A wavelength-converting device is an optical transducing device, which is mainly utilized for converting a wavelength of light into a wavelength of a visible light as a light source. Usually, it is applied to special lightings, such as spotlights, headlights, monitor lightings or projector lightings.
In general, most of conventional wavelength-converting devices are phosphor wheels. A phosphor wheel is used for transforming a light of a laser source into color lights with different wavelengths. Under the high-power operation, the optical converting efficiency of a phosphor wheel can significantly enhance the photoelectric conversion and the luminance output of a projector, such that the phosphor wheel becomes an important light source of new generation projection technology in recent years.
The common projector is provided with blue light laser and a conventional wavelength-converting device having a notch. Please refer to FIG. 1. FIG. 1 schematically illustrates a conventional wavelength-converting device having a notch of prior art. The conventional wavelength-converting device 1 is driven by a motor 2. Phosphor powder 4 is coated on the partial region 30 of a substrate 3. The substrate 3 of the conventional wavelength-converting device 1 is designed to have a notch 31 for controlling the blue light laser to transmit through the notch 31. By adjusting the size of the notch 31, the amount of the blue light laser that transmitting through the notch 31 can be adjusted. However, since the conventional wavelength-converting device 1 is a rotational member, the swing amount of the motor 2 is difficulty to be precisely controlled in high rotational speed. Meanwhile, the wind shear sound will be produced in high-speed rotation due to the shape of the notch 31, thereby becoming the source of noise. On the other hand, although a glass may be embedded in the notch 31 to reduce the noise, the glass may be separated from the substrate 3 in high-speed rotation due to the centrifugal force. Under this circumstance, the conventional wavelength-converting device 1 may be damaged, and even causing the dangers of users.
There is a need of providing a wavelength-converting device and an illumination system using the same to obviate the drawbacks encountered from the prior art.